Light emitting device

ABSTRACT

A light emitting device includes a first lead, a second lead, an insulating member, a diffusing agent-containing portion, a wavelength conversion portion and a lens portion. The insulating member is configured to fix the first lead and the second lead. A thickness of the insulating member is equal to the thickness of the first and second leads. A groove or a recessed portion is provided to retain the wavelength conversion portion in a specific region is formed in the first lead. A second groove portion or recessed portion is formed in the first lead inner side of the groove portion or the recessed portion, which is filled with the diffusing agent-containing portion.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. patent applicationSer. No. 14/247,891 filed on Apr. 8, 2014. This application claimspriority to Japanese Patent Application No. 2013-083755, filed on Apr.12, 2013. The entire disclosures of U.S. patent application Ser. No.14/247,891 and Japanese Patent Application No. 2013-083755 are herebyincorporated herein by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to a light emitting device.

2. Background Art

In recent years, a semiconductor light emitting device has been proposedthat mounts a light emitting element on a main surface of a lead framethat is configured as a package exhibiting superior heat dissipatingperformance. The semiconductor light emitting device is configured tonot interpose a material exhibiting high thermal resistance such as aninsulating substrate or the like in the heat dissipation channel thatradiates heat produced by the light emitting element to the outside.

For example, the light emitting element in a light emitting deviceconfigured for a use such as illumination is covered by a sealing memberthat contains a wavelength conversion material such as a fluorescentmaterial or the like to thereby configure a white light emitting device.More specifically, a thermosetting resin is formed on this type of lightemitting device in order to cover the light emitting element and a wire,and thereby configure a light emitting device that is enabled to emitwhite light by inclusion of a fluorescent material in the sealing resin(JPA 2008-227166).

SUMMARY

A light emitting device has: a first lead which is mounted a lightemitting element, a second lead separated by an interval from the firstlead, an insulating member configured to fix the first lead and thesecond lead, a wavelength conversion portion configured to cover thelight emitting element, and a lens portion configured to cover thewavelength conversion portion, a thickness of the insulating member isequal to the thickness of the first lead and the second lead, a grooveor a recessed portion is provided to retain the wavelength conversionportion in a specific region is formed in the first lead, and a lowersurface of the first lead that forms an opposite side of a region formedon the wavelength conversion portion is not covered by the insulatingmember and is exposed to the outside.

Another light emitting device has: a first lead which is mounted a lightemitting element, a second lead separated by an interval from the firstlead, an insulating member configured to fix the first lead and thesecond lead, a diffusing agent-containing portion configured to coverthe light emitting element, a wavelength conversion portion configuredto cover the diffusing agent-containing portion, and a lens portionconfigured to cover the wavelength conversion portion, a thickness ofthe insulating member is equal to the thickness of the first lead andthe second lead, a groove or a recessed portion is provided to retainthe wavelength conversion portion in a specific region is formed in thefirst lead, and a lower surface of the first lead that forms an oppositeside of a region formed on the wavelength conversion portion is notcovered by the insulating member and is exposed to the outside.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic sectional view illustrating a first embodiment ofa light emitting device according to the present invention, and FIG. 1Bis a schematic plan view of the light emitting device illustrated inFIG. 1A.

FIG. 2A is a schematic sectional view illustrating a second embodimentof a light emitting device according to the present invention, and FIG.2B is a schematic plan view of the light emitting device illustrated inFIG. 2A.

FIG. 3A is a schematic plan view illustrating a resin molded bodyaccording to the first embodiment of a light emitting device accordingto the present invention, and FIG. 3B is a schematic sectional viewalong the line Ill-III of a lead frame illustrated in FIG. 3A.

FIG. 4A and FIG. 4B illustrate a method of manufacturing the resinmolded body according to the first embodiment of a light emitting deviceaccording to the present invention.

FIG. 5 is a schematic sectional view illustrating a third embodiment ofa light emitting device according to the present invention.

FIG. 6 is a schematic sectional view illustrating a fourth embodiment ofa light emitting device according to the present invention.

FIG. 7 is a schematic sectional view illustrating a fifth embodiment ofa light emitting device according to the present invention.

FIG. 8 is a schematic sectional view illustrating a sixth embodiment ofa light emitting device according to the present invention.

FIG. 9 is a schematic sectional view illustrating a seventh embodimentof a light emitting device according to the present invention.

FIG. 10 is a schematic sectional view illustrating an eighth embodimentof a light emitting device according to the present invention.

FIG. 11 is a schematic sectional view illustrating a ninth embodiment ofa light emitting device according to the present invention.

FIG. 12A is a schematic view illustrating an embodiment of a grooveportion, and FIG. 12B is a schematic view illustrating an embodiment ofa recessed portion of a light emitting device according to the presentinvention.

FIG. 13 is a schematic sectional view illustrating an embodiment of alight emitting device according to the present invention.

FIG. 14A is a schematic sectional view illustrating a tenth embodimentof a light emitting device according to the present invention, and FIG.14B is a schematic plan view of the light emitting device illustrated inFIG. 14A.

FIGS. 14C to 14F are schematic sectional views illustrating modifyingembodiments of the first leads of a light emitting device according tothe present invention.

FIG. 15 is a schematic sectional view illustrating a eleventh embodimentof a light emitting device according to the present invention.

FIG. 16 is a schematic sectional view illustrating a twelfth embodimentof a light emitting device according to the present invention.

DETAILED DESCRIPTION

Embodiments for implementing the light emitting device of the presentinvention will be described below with reference to the accompanyingdrawings. The sizes and the arrangement relationships of the members ineach of drawings are occasionally shown exaggerated for ease ofexplanation. Further, in the description below, the same designations orthe same reference numerals may, in principle, denote the same or likemembers and duplicative descriptions will be appropriately omitted.Terms indicating a specific direction or position are used as requiredin the following description (for example, “above”, “below”, “right”,“left”, and other terms including those terms). However, these terms arefor the purpose of facilitating comprehension of the invention byreference to the figures, and do not limit the technical scope of theinvention as a result of the meaning of these terms.

In the present specification, terms such as resin substrate, insulatingmember and lead are used in relation to the light emitting device afterformation into separate units, and terms such as lead frame and resinmolded body are used in relation to the stage prior to formation intoseparate units.

First Embodiment

The light emitting device 100 according to the first embodiment of thepresent invention is shown in sectional view in FIG. 1A. FIG. 1B is aschematic plan view illustrating the light emitting device 100, and FIG.1A is a schematic sectional view along the line I-I of a lead frameillustrated in FIG. 1B.

A light emitting device 100 principally includes a first lead 12, asecond lead 14, an insulating member 20 configured to fix these leads, alight emitting element 10 mounted on the first lead 12, a wavelengthconversion portion 16 configured to cover the light emitting element 10and a lens portion 18 configured to cover the wavelength conversionportion 16.

The first lead 12 and the second lead 14 are integrally formed by theinsulating member 20. That is to say, as illustrated in FIG. 1A, thefirst lead 12 and the second lead 14 are separated by an interval, andthe insulating member 20 is embedded to fill that interval. Thethickness of the first lead 12 and the second lead 14 is approximatelyequal to the thickness of the insulating member 20. The first lead 12,the second lead 14 and the insulating body 20 form a resin substrate 30.As illustrated in FIG. 1B, the resin substrate 30 has a tabularconfiguration, and the upper surface and the lower surface of the firstlead 12 and the second lead 14 are exposed on its upper surface andlower surface. In other words, the upper surface and the lower surfaceof the first lead 12, the second lead 14 and the insulating member 20are configured to be flush, respectively.

As illustrated in FIG. 1B, the first lead 12 is configured to project ina direction facing the second lead 14, and the second lead 14 has adepressed configuration with reference to the projection of the firstlead 12. A projecting portion of the first lead 12 is formed in a curvedshape that is concentric with the circle of a groove portion 26 alongthe shape of the groove portion 26 described below in approximately thecenter in a vertical direction. In this manner, the region in which thelight emitting element 10 on the first lead 12 is mounted is configuredto be substantially in the center of the light emitting device 100. Thatis to say, it is preferred that the first lead 12 projects to enable thepositioning of the light emitting element 10 substantially in the centerof the light emitting device 100.

The groove portion 26 to retain the wavelength conversion portion 16 ina specific region is formed in the first lead 12. The groove portion 26has a circular shape when in a plan view as illustrated in FIG. 1B, andfour light emitting elements 10 are disposed in the region surrounded bythe groove portion 26. As illustrated in FIG. 1A, the first lead 12 hasa thin configuration in the thickness direction for defining the grooveportion 26. Therefore, the bottom face of the groove portion 26, i.e.,an opening of the first lead 12 that forms the groove portion 26 isformed to be positioned below the surface that mounts the light emittingelement 10.

As illustrated in FIG. 1A, the shape of the opening of the grooveportion 26 preferably describes a right angle or acute angle between thesurface on the inner side that forms the groove and the surface thatmounts the light emitting element. Since the end portion of thewavelength conversion portion 16 is formed in the shape of the openingby a pin lock effect, the extent of the shape of the wavelengthconversion portion 16 is defined, and a protruding shape of thewavelength conversion portion 16 exhibits a stable formation. Thewavelength conversion portion 16 is formed as a hemisphere since thewavelength conversion portion 16 is configured in a protruding shapethat projects from the light emitting element mounting surface, andtherefore a light emitting device can be realized that exhibits a lowvariation in light distribution and chromaticity, and particularlysuperior light quality.

According to an embodiment of the present invention, variation in lightquality can be suppressed, and superior illumination quality is obtainedeven when beam condensing is performed by use of a beam-condensingdevice.

That is to say, the embodiment of the present invention is completed inlight of the problems below, the coverage of the sealing resin thatincludes the fluorescent material tends to be affected by the viscosityof the resin and the peripheral temperature, and therefore light qualitycan not exhibit stable characteristics. In other words, the region ofdisposition of the fluorescent material can not be stable. Consequently,the periphery of the light emitting element is illuminated with bluecolor and locations more removed from the light emitting element areilluminated with a yellow color, and it may results in the problem of alarge variation in light quality. Furthermore, since the region ofdisposition of the fluorescent material is large, there may be theproblem that there is a large difference in relation to chromaticitybetween the periphery of the light emitting element and the locationsmore removed from the light emitting element.

As illustrated in FIG. 12A, the distance X from the surface on the innerside that forms a groove of the groove portion 26 to the most proximatelight emitting portion 10 is preferably at least 1 micron, and at least5 microns is more preferred. When the distance X is small, it is notpossible to insert a wavelength conversion material having a graindiameter that is larger than X into this region, and therefore, thecontent amount of the wavelength conversion material in the region isreduced which therefore results in failure to convert the light from thelight emitting element 10 to a desired wavelength. Consequently,although it is preferred that the distance X is greater than the averagegrain diameter of the wavelength conversion material (fluorescentmaterial) that is used, when light quality is taken into account, it ispreferred that X is no more than 5 microns. It is known that the lightextraction efficiency is enhanced when the grain diameter of thewavelength conversion unit is large, and therefore a configuration of 1micron to 50 microns is suitable. More preferably, a configuration of 3microns to 40 microns is preferred.

There is no particular limitation on the number and disposition of thelight emitting elements 10, and one or a plurality may be provided.However, it is preferred that a balanced configuration is provided inrelation to disposition with line symmetry or point symmetry on theregion surrounded by the groove portion 26 in order to enhance the lightquality. Herein, a plurality (four) light emitting elements is disposed.The surface of the light emitting elements 10 that is mounted on thefirst lead 12 exhibits insulating characteristics, and has positiveelectrode and negative electrode on an upper surface, that is to say, isconfigured as a face-up light emitting element. The positive electrodeand negative electrode of the light emitting element 10 are electricallyconnected to the first lead 12 and the second lead 14 by wire 24,respectively.

The area of the lower surface of the light emitting element 10 that isin contact with the first lead 12 is preferably at least 10% of thesurface area of the region forming the wavelength conversion portion 16(surface area of the region surrounded by the groove portion 26), whichis the upper surface of the first lead 12. When the surface area of thelower surface of the light emitting element 10 is less than 10%, thecolor tone at a location separated from the light emitting element andin proximity to the light emitting element undergoes a large variation.For example, when a fluorescent material that emits yellow light and alight emitting element that emits blue light are used, since there is alarge amount of the fluorescent material at a position separated fromthe light emitting element, there is a greater tendency for a yellowcolor tone comparing to the proximity to the light emitting element. Asa result, yellow ring phenomenon is conspicuous, the light distributionand chromaticity of the light emitting device is adversely affected, andthe light quality is poor.

The wavelength conversion portion 16 contains a wavelength conversionmaterial configured to convert the wavelength of light from the lightemitting element 10, and is configured to cover the light emittingelement 10. The lower surface of the wavelength conversion portion 16 isformed on the inner side of the region surrounded by the groove portion26, a portion of the wire 24 is covered by the wavelength conversionportion 16, and the residual portion of the wire 24 is covered by a lensportion 18 provided on an outer side.

The wavelength conversion portion 16 is formed only on the first lead12, and is not formed on the second lead 14 or the insulating member 20.That is to say, the insulating member 20 is not contacted with thewavelength conversion portion 16. In this manner, even in aconfiguration in which the insulating member 20 exhibits a low opticalreflectance, since there is almost no effect on the light extractionefficiency, a cheap resin material can be used without considering thereflectance. Furthermore, since the light from the light emittingelement is efficiently reflected by a metallic member such as the lead,the light extraction efficiency can be enhanced.

The lens portion 18 is formed to cover the wavelength conversion portion16. In the present embodiment, the lower surface of the wavelengthconversion portion 16 only comes into contact with the first lead 12,and from that position upwardly, a protruding lens portion 18 isconfigured to cover all the wavelength conversion portion 16. Herein,the shape of the lens is hemispherical.

Herein, the lower surface of the first lead 12 that forms the oppositeside of the region formed on the wavelength conversion portion 16 (theportion shown by A in FIG. 1A) is not covered by the insulating member20 and is exposed to the outside. In this manner, when mounting thelight emitting device 100 on the mounting substrate, heat produced bythe light emitting element 10 and the wavelength conversion portion 16can be efficiently drew into the mounting substrate, and thereby enhancethe light emission efficiency.

As described above, the light emitting device 100 can be realized thatexhibits superior light quality and high light emission efficiency.

Detailed description of the constituent members of the light emittingdevice 100 will be given below.

First Lead 12, Second Lead 14

The first lead 12 and the second lead 14 for example is formed using agood electrical conductor such as iron, copper, phosphor bronze, copperalloys, Iron-based alloys such as alloy 42, or a clad member laminatedusing such materials. Processing by use of pressing, etching or a laserprocess is also possible. Furthermore, as required, metal plating may beperformed on the surface. The plating material includes Ag, Ag alloys,Au, Au alloy, Cu, Ni, Pd or the like. The outermost surface of platingis preferably Ag, an Ag alloy, Au or an Au alloy. Ag, Ag alloys, Au, Aualloy, Cu, Ni, Pd and the like may be laminated as an underline.

The thicknesses of the first lead 12 and the second read 14 arepreferably 50 to 1000 microns, respectively, and preferably 100 to 500microns. The depth of the groove is preferably 10 to 80% of thethickness of the first lead 12. When the groove is excessively shallow,the wavelength conversion portion 16 leaks out and cannot be properlyretained. When the groove is excessively deep, light entering the groovecannot come out again, and therefore light emission efficiency is poor.

The first lead 12 and the second lead 14 are preferably configured withan uneven structure in order to enhance the attachment characteristicswith the insulating member 20. In this manner, the attachment surfacearea between the leads and the insulating member 20 is increased, andthereby attachment characteristics are enhanced. The uneven structure ispreferably formed from the surface of the leads towards the sidesurface, and may be formed by etching or press processing.

Insulating Member 20

A resin can be employed suitable for the insulating member 20. Examplesof such resin preferably include thermoplasticity resins containing atleast one of an acrylate resin, an aromatic polyamide resin, a polyesterresin, a liquid crystal resin, and thermosetting resins containing atleast one of an epoxy resin, a modified epoxy resin, a phenolic resin, asilicone resin, a modified silicone resin, a hybrid resin, an urethaneresin. An epoxy resin, a modified epoxy resin, a silicone resin, amodified silicone resin, a hybrid resin and the like are preferable.

The insulating member 20 may include at least one of a diffusion agent,a high thermal conductivity material, a reinforcing material, anantioxidant agent, an ultraviolet absorbing material, a lightstabilizer, a lubricant and the like. Examples of the diffusion materialinclude at least one titanium oxide, zirconium oxide, aluminum oxide,silicon oxide, boron oxide, hollow filler and the like. Examples of thereinforcing material include whiskers, glass fibers and the like.

Examples of the high thermal conductivity material include boronnitride, aluminum nitride, aluminum oxide and the like. Examples of theantioxidant include phenol-based, sulfur-based phosphorus-based,amine-based and other agents. Examples of the lubricant include a higherfatty acid ester, silicone-based, fluorine-based and other agents.Additives such as UV absorbers and light stabilizers may be included.

Wavelength Conversion Portion 16

The wavelength conversion portion 16 contains a wavelength conversionmaterial in the resin material. Examples of the resin material includethermoplasticity resins containing at least one of an acrylate resin, anaromatic polyamide resin, a polyester resin, a liquid crystal resin, andthermosetting resins containing at least one of an epoxy resin, amodified epoxy resin, a phenolic resin, a silicone resin, a modifiedsilicone resin, a hybrid resin, an urethane resin. An epoxy resin, amodified epoxy resin, a silicone resin, a modified silicone resin, ahybrid resin and the like are preferable.

The resin material may include a mixture of a diffusion agent or thelike in order to maintain a predetermined function. Examples of thediffusing agent include at least one of titanium oxide, zirconium oxide,aluminum oxide, silicon oxide, boron oxide, hollow filler and the like.Further, the nano materials such as nano titanium oxide, nano-zirconiumoxide, nano-aluminum oxide, nano-silicon oxide, nano-boron oxide and thelike may be used. The average particle diameter is preferably 1 nm to 50microns, and more preferably, 5 nm to 20 microns.

Wavelength Conversion Member

There is no particular limitation on the wavelength conversion member aslong as the light emitted from the light emitting element is convertedto the light having the desired wavelength. Examples of the wavelengthconversion member include a YAG-based fluorescent material (yello togreen fluorescent material), LAG-based fluorescent material (yellow togreen fluorescent material), oxy-nitride fluorescent material that ismainly activated by europium, cerium, and other such lanthanoidelements, nitride fluorescent material that is mainly activated byeuropium, cerium, and other such lanthanoid elements. Examples ofeuropium-doped red fluorescent material include SCASN fluorescentmaterial such as (Sr, Ca)AlSiN₃:Eu or the like, CASN fluorescentmaterial such as CaAlSiN₃:Eu, SrAlSiN₃:Eu, or the like. Furtherchlorosilicate fluorescent materials, β sialon fluorescent materials orthe like that emits green light and absorbs blue light emitted fromlight emitting element.

Lens Portion 18

A resin material is preferably used in the lens portion 18. Examples ofthe resin material include thermoplasticity resins containing at leastone of an acrylic resin, a polycarbonate resin, an aromatic polyamideresin, a polyester resin, a liquid crystal resin, thermosetting resinscontaining at least one of an epoxy resin, a modified epoxy resin, aphenolic resin, a silicone resin, a modified silicone resin, a hybridresin, an urethane resin, and inorganic materials such as at least oneof a low-melting-point glass and water glass. An epoxy resin, a modifiedepoxy resin, a silicone resin, a modified silicone resin, a hybrid resinand the like are preferable, and a silicone resin, a modified siliconeresin, a hybrid resin are more preferable.

The lens portion 18 may maintain a predetermined function by mixture ofat least one substance selected from the group comprising of a diffusionagent and a high thermal conductivity material. Examples of thediffusing agent include titanium oxide, zirconium oxide, aluminum oxide,silicon oxide, boron oxide and the like. The average particle diameteris preferably 0.1 microns to 50 microns, and more preferably, 0.5microns to 40 microns. Further, the nano materials such as nano titaniumoxide, nano-zirconium oxide, nano-aluminum oxide, nano-silicon oxide,nano-boron oxide and the like may be used. The average particle diameteris preferably 1 nm to 100 nm, and more preferably, 5 nm to 90 nm.Examples of the high thermal conductivity materials may include aluminumoxide, boron nitride, nano diamond and the like. The wavelengthconversion materials which absorb the light emitted from the lightemitting element and converts the wavelength of the light can becontained in the lens portion 18.

The lens portion 18 preferably has the function of refracting,dispersing or focusing light, and in response to various purposes, thelens portion 18 may have various configurations such as a lens with asmaller curvature than a hemisphere, or a hemispherical shape, or a lenswith a larger curvature than a hemisphere. A desired light distributionis obtained by the lens portion 18. On the other hand, when focusinglight from the light emitting element 10 with the lens portion 18, therehas been the problem that the color deviation in proximity to the lightemitting element is accentuated through the mediation of the lensportion, and consequently the illumination light exhibits a colordeviation (color shading) such as so-called yellow ring. In the presentembodiment, since color deviations in proximity to the light emittingelement can be suppressed, superior illumination quality as demanded bythe market can be obtained even when focusing by use of the lens portion18.

Light Emitting Element 10

The light emitting element 10 is preferably a light emitting diode. Forexample, it is possible to use a configuration having a light emissionpeak wavelength of 350 nm to 800 nm. In particular, when using a lightemitting element configured from a nitride-based semiconductor, it ispreferred to use a configuration having a light emission peak wavelengthof 420 nm to 550 nm in the short wavelength region of visible light.

Other

The light emitting device 100 as illustrated in FIG. 1B further includesa protective element 32. The protective element is suitably configuredas a Zener diode for example. The protective element 32 is preferablydisposed in the outer region of the groove portion 26 mounted on thelight emitting element 10. In this manner, absorption of light from thelight emitting element 10 by the protective element 32 can besuppressed, and it is possible to suppress a reduction in the lightextraction efficiency of the light emitting device 100. Furthermore, aneffect on light distribution characteristics can be suppressed, andlight quality enhanced.

Method of Manufacturing Light Emitting Device 100

As illustrated in FIG. 4A, a first processing step comprises sandwichingof the lead frame 34 with an upper die 46 and lower die 48. Then asillustrated in FIG 4B, the insulating member 20 is transfer molded intoa die sandwiched by the upper die 46 and the lower die 48. Heatprocessing is executed in an oven to cure the resin and integrally formthe insulating member 20 in the lead frame 34 and thereby form a resinmolded body 44. The resin molded body 44 formed in the above manner isillustrated in FIG. 3.

The lead frame 34 is configured so that a plurality of first leads 12and second leads 14 that form the light emitting device 100 areconnected. As illustrated in FIG. 3A, thereafter, the portion formingthe first lead 12 and the portion forming the second lead 14 may beconnected in a horizontal direction by a suspension lead 36, and thevertically adjacent pairs of first leads 12 may be connected by asuspension lead 38. The vertically adjacent pairs of second leads 14 maybe connected by a suspension lead 40. Furthermore, the pairs ofvertically adjacent portions forming the first lead 12 and thevertically adjacent portions forming the second lead 14 may be connectedto a suspension lead 42 that extends in an inclining direction. Thesuspension 42 may or may not be provided.

The method of molding is preferably transfer molding, but also includesinjection molding, compression molding, and extrusion molding.

A hole 50 to enhance the attachment with the insulating member 20 ispreferably provided on the lead frame 34. In this manner, detachment orpeeling of the insulating member 20 from the lead frame 34 can besuppressed. A recessed portion may be formed in the lead frame 34 inorder to enhance the attachment characteristics with the lens portion18. The recessed portion is formed by half-etching the lead flame 34.The recessed portion 21 a may have a circular shape, a band shape, acurved band shape, polygonal shape, or the like when viewed in plan.

Next, in a second processing step, electric deflash processing isperform to remove resin burrs on the resin molded body surface producedby transfer molding, and then the resin burrs are removed with a waterjet. Electric deflash processing is a process by immersion of the resinmolded body in a solution, execution of electrolysis in that state, andswelling of the thin resin pieces attached to the lead frame, that is tosay, swelling of the burrs. Removal of resin burrs enhances thereliability of wire bonding, the mounting of the protective element, andthe mounting of the light emitting element described hereafter. Removalof resin burrs may also be performed by chemical dip processing, blastprocessing or laser processing.

In a third processing step, a bonding material is coated onto theposition for mounting of the light emitting element 10 being on theinner side of the groove portion 26 of the portion forming the firstlead 12 to thereby mount the light emitting element 10. Next, heatprocessing is performed in an oven to cure the bonding material.Examples of the bonding material include thermosetting resins containingat least one of an epoxy resin, a modified epoxy resin, a phenolicresin, a silicone resin, a modified silicone resin, a hybrid resin, anurethane resin, and inorganic materials such as at least one of alow-melting-point glass, water glass and hydraulic cement. A modifiedepoxy resin, a silicone resin, a modified silicone resin, a hybrid resinand the like are preferable, and a silicone resin, a modified siliconeresin, a hybrid resin are more preferable.

In a fourth processing step, a conductive bonding material is coated tothe position of mounting of the protective element that is the outerside of the groove portion 26 of the first lead 12 to thereby mount theprotective element. Next, heat processing is performed in an oven tocure the bonding material. The conductive bonding material is preferablyconfigured for example as an Ag paste.

In a fifth processing step, the light emitting element 10 and theportions forming the first lead 12 and forming the second lead 14,respectively, and the portion forming the second lead 14 and theprotective element 32 are respective electrically connected by the wires24 by use of a wire bonding apparatus.

In a sixth processing step, resin that includes the wavelengthconversion material is coated from above the light emitting element 10using a resin coating apparatus, and then subjected to thermalprocessing in an oven to cure the resin.

The wavelength conversion portion 16 is configured with a protrudingshape by a pin lock effect from the groove portion 26.

In a seventh processing step, the resin molded body obtained in thesixth step is placed in a heated lower die, coating with the resin forformation of the lens portion 18, and then, the resin molded body issandwiched with the die, and a resin molded body is removed thatincludes formation of a protruding lens portion 18. Thermal processingin an oven is performed to cure the lens portion 18.

The method of forming the lens portion 18 includes use of variousmethods such as transfer molding, compression molding, resin coating(potting), molding by use of a casting case, or the like. When moldingby use of compression molding, a flat portion 52 is formed in theperiphery of the lens portion 18 as illustrated in FIG. 13 as a lightemitting device 110. The light emitting device according to theembodiment configures the resin molded body 44 substantially with thethickness of the lead frame, and therefore enables extremely thinmolding in comparison to a conventional light emitting device.Therefore, the provision of the flat portion 52 in the lens portion 18enables a configuration of a light emitting device with sufficientstrength even when the thickness of the resin molded body is low.

Finally, in an eighth processing step, the resin substrate obtained inthe seventh step is adhered to the dicing sheet, and the insulatingmember 20 is cut with a dicing blade through the suspension leads 36,38, 40, and 42 to thereby obtained individual light emitting devices100.

Second Embodiment

The light emitting device 200 according to the second embodiment of thepresent invention is shown in sectional view in FIG. 2A. FIG. 2B is aschematic plan view illustrating the light emitting device 200, and FIG.2A is a schematic sectional view along the line I-I of a lead frameillustrated in FIG. 2B.

A light emitting device 200 differs from the first embodiment inrelation to the point that a recessed portion 28 is provided insubstitution for the groove portion in the first lead 12. In otherrespects, the second embodiment is substantially the same to the firstembodiment.

The recessed portion 28 is formed in the first lead 12 in order toretain the wavelength conversion portion 16 in a specific region. In thepresent embodiment, as illustrated in FIG. 2B, the recessed portion 28has a circular shape when viewed in plan. Four light emitting elements10 are disposed on the recessed portion 28. As illustrated in FIG. 2A,the recessed portion 28 is formed by reducing the thickness of a portionof the first lead 12. That is to say, the bottom surface of the recessedportion that mounts the light emitting element 10 is positioned belowthe upper surface of the insulating member 20.

The depth of the recessed portion 28 is preferably 5 to 70% relative tothe thickness of the first lead 12. When the depth of the recessedportion is excessively shallow, the wavelength conversion portion 16leaks out and cannot be properly retained. When the recessed portion isexcessively deep, light leaving the light emitting element and thewavelength conversion portion is retained in the recessed portion, andtherefore light extraction efficiency is poor.

The wavelength conversion portion 16 is formed to fill the recessedportion 28. The wavelength conversion portion 16 may be formed in aprotruding configuration as illustrated in FIG. 2A, may be formed in arecessed configuration, or may have a flat upper surface. Furthermore,the upper surface of the wavelength conversion portion 16 may bepositioned more on an upper side than the surface of the first lead 12,the second lead 14 and the insulating member 20, or may be positioned ona lower side.

The method of manufacturing the light emitting device 200 according tothe second embodiment may be the same as the method of manufacturing thelight emitting device 100 according to the first embodiment by use of alead frame forming a recessed portion in substitution for the grooveportion.

The light emitting device 200 can be realized that exhibits superiorlight quality and high light emission efficiency. Further, since a largeamount of light is emitted from the opening of the recessed portiontoward the upper surface due to the enablement of light reflection inthe recessed portion 28, the light emitting surface area can be reducedand thereby obtain well-defined light quality.

As illustrated in FIG. 12B, the distance X from the surface on the innerside that forms a groove of the recessed portion 28 to the mostproximate light emitting portion 10 is preferably at least 1 micron, andat least 5 microns is more preferred. When light quality is taken intoaccount, it is preferred that X is no more than 5 microns. This point isthe same in relation to the first embodiment.

Third Embodiment

The light emitting device 300 according to the third embodiment of thepresent invention is shown in plan view in FIG. 5.

The light emitting device 300 differs from the first embodiment inrelation to the point that the groove portion 26 is formed as arectangle when viewed in plan, and two light emitting elements 10 aredisposed in the groove portion 26. In other respects, the thirdembodiment is substantially the same to the first embodiment. Accordingto the present embodiment, the bottom surface of the wavelengthconversion portion 16 is formed along the outer contour of the lightemitting element 10. In this manner, since the light conversion portion16 is configured with a uniform shape along the light emitting element10 outer periphery in proximity to the light emitting element 10, thedifference in the chromaticity of the end portions of the lightconversion portion 16, and the chromaticity in proximity to the lightemitting element 10 can be reduced and therefore superior light qualityis obtained.

The third embodiment obtains the same effect as the first embodiment.

Fourth Embodiment

The light emitting device 400 according to the fourth embodiment of thepresent invention is shown in plan view in FIG. 6.

The light emitting device 400 according to the fourth embodiment of thepresent invention is shown in plan view in FIG. 6. The light emittingdevice 400 differs from the second embodiment in relation to the pointthat the recessed portion 28 is formed as a rectangle when viewed inplan. In other respects, the second embodiment is substantially the sameto the first embodiment.

Since the wavelength conversion portion 16 is formed in proximity to thelight emitting element 10 as a result of forming the wavelengthconversion portion 16 in proximity to the light emitting element 10, thedifference in the chromaticity of the end portions of the lightconversion portion, and the chromaticity in proximity to the lightemitting element can be reduced and a large amount of light is emittedfrom the opening of the recessed portion towards the upper surface.Therefore, the light emission surface area can be reduced andwell-defined light quality is obtained.

The forth embodiment obtains the same effect as the second embodiment.

Fifth Embodiment

The light emitting device 500 according to the fifth embodiment of thepresent invention is shown in plan view in FIG. 7.

The light emitting device 500 differs from the second embodiment inrelation to the point that the upper surface of the light emittingelement 10 may be positioned more on a lower side than the upper surfaceof the first lead 12. In other respects, the fifth embodiment issubstantially the same to the second embodiment.

The light emitting device 500 facilitates a uniform dispersal of thewavelength conversion material in the wavelength conversion portion 16on the upper surface of the light emitting element 10 by formation ofthe upper surface of the light emitting element 10 on a lower side belowthe upper surface of the first lead 12, and thereby enhances lightextraction efficiency and obtains superior light quality.

The fifth embodiment obtains the same effect as the second embodiment.

Sixth Embodiment

The light emitting device 600 according to the sixth embodiment of thepresent invention is shown in plan view in FIG. 8.

The light emitting device 600 differs from the second embodiment inrelation to the point that formation of the lens portion 18 with a lowercurvature than the curvature in the second embodiment, and enablesextraction of a broader distribution of light. In other respects, thesixth embodiment is substantially the same to the second embodiment.

The sixth embodiment obtains the same effect as the second embodiment.

Seventh Embodiment

The light emitting device 700 according to the seventh embodiment of thepresent invention is shown in plan view in FIG. 9.

The light emitting device 700 forms the lens portion 18 with twoprotrusions when viewed in sectional shape, and forms the centralportion in a recessed configuration. This lens configuration enables aso-called batwing light distribution, and enables extraction of light ina broader light distribution than the second embodiment. In otherrespects, the seventh embodiment is substantially the same to the secondembodiment.

The seventh embodiment obtains the same effect as the second embodiment.

Eighth Embodiment

The light emitting device 800 according to the eighth embodiment of thepresent invention is shown in plan view in FIG. 10.

The light emitting device 800 differs from the first embodiment inrelation to the point that formation of the lens portion 18 with a lowercurvature than the curvature in the second embodiment, and enablesextraction of a broader distribution of light. In other respects, thesixth embodiment is substantially the same to the first embodiment. Inother respects, the seventh embodiment is substantially the same to thesecond embodiment.

The eighth embodiment obtains the same effect as the first embodiment.

Ninth Embodiment

The light emitting device 900 according to the ninth embodiment of thepresent invention is shown in plan view in FIG. 11.

The light emitting device 900 forms the lens portion 18 with twoprotrusions when viewed in sectional shape, and forms the centralportion in a recessed configuration. This lens configuration enables aso-called batwing light distribution, and enables extraction of light ina broader light distribution than the first embodiment. In otherrespects, the seventh embodiment is substantially the same to the firstembodiment.

The ninth embodiment obtains the same effect as the first embodiment.

Tenth Embodiment

The light emitting device 120 according to the tenth embodiment of thepresent invention is shown in sectional view in FIG. 14A. FIG. 14B is aschematic plan view illustrating the light emitting device 120, and FIG.14A is a schematic sectional view along the line III-III of a lead frameillustrated in FIG. 14B.

In the light emitting device 120, a recessed portion 28 is provided inthe first lead 12, the recessed portion 28 has a circular shape whenviewed in plan. Four light emitting elements 10 are disposed in thebottom region of the recessed portion 28. As illustrated in FIG. 14B,the recessed portion 28 is formed by reducing the thickness of a portionof the first lead 12. The recessed portion 28 is the same constructionas that of the second embodiment.

The light emitting device 120 differs from the foregoing embodiments inrelation to the point that the groove portion 26 is further formed. Thegroove portion 26 is formed outside of the recessed portion 28 and awayfrom the recessed portion 28 on the first lead 12 formed of the recessedportion 28. The groove portion 26 is the same construction as that ofthe first embodiment.

The wavelength conversion portion 16 is formed to fill the recessedportion 28 so as to cover the light emitting elements 10. The wavelengthconversion portion 16 is stably configured such that the end portion ofthe wavelength conversion portion 16 is positioned in the upper part ofthe inner surface of the groove portion 26 by a pin lock effect from thesurfaces formed of the inner surface of the groove portion 26 and theupper face of the first lead 12. Therefore, the height of the protrudingshape can be higher than a protruding shape of the wavelength conversionportion which is formed by only the recessed portion. The light emittingelement positioned in the vicinity of the outside of the recessedportion can be covered by sufficient quantities of the wavelengthconversion portion 16. Consequently, the color shading can be furtherimproved.

Second Groove Portion or Recessed Portion

A second groove portion or recessed portion may be formed in the firstlead 12 inside or outside of the groove portion or the recessed portionto retain the wavelength conversion portion 16 or the like in a specificarea in the same matter of the groove portion or the recessed portion.As illustrated in FIG. 14C, the grove portion 26 is formed as the secondgroove portion outside of the recessed portion 28 in FIGS. 14A and 14B.Also, the first lead 12 may has a groove portion 26 as a second grooveportion outside of the recessed portion 28 s as illustrated in FIG. 14D,a recessed portion 26 a as a second recessed portion outside of therecessed portion 28 as illustrated in FIG. 14E, a recessed portion 26 aas a second recessed portion outside of the groove portion 28 a asillustrated in FIG. 14F. The wavelength conversion portion 16, lensportion 14 or a diffusing agent-containing portion described below canbe filled in the second groove portion or recessed portion.

Recessed portions 21 a are formed in the first lead 12 in order toenhance the attachment characteristics with the lens portion 18. Therecessed portion 21 a has a circular shape when viewed in plan.Similarly recessed portions 21 b are formed in the second lead 14 andhave a curved band shape when viewed in plan. These recessed portions 21a, 21 b are formed by half-etching the first lead 12 and the second lead14.

Eleventh Embodiment

The light emitting device 130 according to the eleventh embodiment ofthe present invention is shown in sectional view in FIG. 15.

The light emitting device 130 differs from the tenth embodiment inrelation to the point that the diffusing agent-containing portion 54 isformed to fill the recessed portion 28 in the same manner of the secondembodiment, and the wavelength conversion portion 16 is formed in aprotruding configuration on the diffusing agent-containing portion 54 soas to cover the diffusing agent-containing portion 54 by a pin lockeffect from the groove 26, thus, two layers are positioned on therecessed portion 28. In other respects, the eleventh embodiment issubstantially the same to the tenth embodiment. Covering a plurality ofthe light emitting elements 10 by the diffusing agent-containing portion54 can create a state in which the whole diffusing agent-containingportion 54 radiates lump of light. Consequently, the color shading canbe inhibited by formation of the wavelength conversion portion 16 on thediffusing agent-containing portion 54.

Diffusing Agent-Containing Portion 54

The diffusing agent which is contained in the wavelength conversionportion 16 can be positioned as a diffusing agent-containing portion 54independently from the wavelength conversion portion 16 containing thewavelength conversion member described above. The diffusingagent-containing portion 54 can be formed from at least one diffusingagent and at least one resin material. The same resin material as thatof the wavelength conversion portion can be preferably used, and thesame diffusing agent as that of the wavelength conversion portion can bepreferably used. The resin material of the wavelength conversion portionand the resin material of the diffusing agent-containing portion may bethe same or different to each other. Also, the diffusing agent of thewavelength conversion portion and the diffusing agent of the diffusingagent-containing portion may be the same or different to each other.

Twelfth Embodiment

The light emitting device 140 according to the twelfth embodiment of thepresent invention is shown in sectional view in FIG. 16.

The light emitting device 140 differs from the tenth embodiment inrelation to the point that a resin portion 55 which does not contain thediffusing agent, in stead of the diffusing agent-containing portion 54,is formed to fill the recessed portion 28 in the same manner of thesecond embodiment, and the wavelength conversion portion 16 is formed ina protruding configuration on the resin portion 55 so as to cover theresin portion 55 by a pin lock effect from the groove 26, thus, twolayers are positioned on the recessed portion 28. In other respects, thetwelfth embodiment is substantially the same to the tenth and theeleventh embodiment. Covering the light emitting elements 10 by theresin portion 55 which does not contain the diffusing agent caneffectively reflect light emitted from the light emitting element 10 atthe interface of the resin portion 55 and the wavelength conversionportion 16. Further, the reflected light can be reflected again at thesurface of the first lead 12 in which the light emitting element is notinsulated. As a result, the light extraction efficiency can be enhanced.Moreover, there may be no material which blocks and/or absorbs thelight, thus the light emitted form the light emitting element andreflected light described above can travel within the whole resinportion 55. Consequently, the color shading can be inhibited.

Resin Portion 55

The resin portion 55 can be disposed under the wavelength conversionportion 16, in stead of or with the diffusing agent-containing portion54. The resin portion 55 can be formed from at least one resin material.The same resin material as that of the wavelength conversion portion 16and/or the diffusing agent-containing portion 54 can be preferably used.The resin material of the resin portion 55, the resin material of thewavelength conversion portion and the resin material of the diffusingagent-containing portion may be the same or different to each other.

The light emitting device according to the present invention can be usedfor various kinds of light sources, such as illumination light sources,light sources for various kinds of indicators, light sources forautomobile use, light sources for displays, back light sources forliquid crystal displays, light sources for sensors, signals, automobileuse, channel control characters for channel boards.

As illustrated above, embodiments are described to give a concrete formto technical ideas of a method of manufacturing light emitting elementaccording to the present invention, the present invention is not limitedto the described embodiments of the present invention. Also, obviously,numerous modifications and variations of the present invention arepossible in light of the above teachings, which are within the scope andspirit of the invention, and such other modifications and variations areintended to be covered by the following claims.

What is claimed is:
 1. A light emitting device comprising: a first leadwhich is mounted a light emitting element; a second lead separated by aninterval from the first lead; an insulating member configured to fix thefirst lead and the second lead; a diffusing agent-containing portionconfigured to cover the light emitting element; a wavelength conversionportion configured to cover the diffusing agent-containing portion; anda lens portion configured to cover the wavelength conversion portion,wherein a thickness of the insulating member is equal to the thicknessof the first lead and the second lead, a groove or a recessed portionprovided to retain the wavelength conversion portion in a specificregion is formed in the first lead, and a second groove portion orrecessed portion is formed in the first lead inner side of the grooveportion or the recessed portion, which is filled with the diffusingagent-containing portion.
 2. The light emitting device according toclaim 1, wherein a lower surface of the first lead that forms anopposite side of a region formed on the wavelength conversion portionand the diffusing agent-containing portion is not covered by theinsulating member and is exposed to the outside.
 3. The light emittingdevice according to claim 1, wherein the insulating member is not incontact with the wavelength conversion portion.
 4. The light emittingdevice according to claim 1, wherein the light emitting element iselectrically connected to the second lead by wire, and the wire iscovered by the wavelength conversion portion and lens.
 5. The lightemitting device according to claim 1, wherein the area of the lowersurface of the light emitting element that is in contact with the firstlead is at least 10% of the area of the region forming the wavelengthconversion portion, which is the upper surface of the first lead.
 6. Thelight emitting device according to claim 1, wherein the first lead isconfigured to project in a direction facing the second lead, and thesecond lead has a depressed configuration with reference to theprojection of the first lead.
 7. The light emitting device according toclaim 1, wherein a plurality light emitting elements is disposed.